Finger brake radius question
Close
Login to Your Account
Results 1 to 9 of 9
  1. #1
    Join Date
    Sep 2010
    Location
    Oklahoma City, OK
    Posts
    4,249
    Post Thanks / Like
    Likes (Given)
    730
    Likes (Received)
    1784

    Default Finger brake radius question

    I recently picked up a small finger brake to make some aluminum boxes and what I'm wondering is how to properly determine the bend radius for specific thicknesses of sheet metal. Right now it's all 14 or 16 gauge aluminum.

    Does anyone have other rules of thumb they'd like to share?

    Thanks, Cole

  2. #2
    Join Date
    Jan 2010
    Country
    UNITED STATES
    State/Province
    North Carolina
    Posts
    170
    Post Thanks / Like
    Likes (Given)
    267
    Likes (Received)
    90

    Default

    Here's a decent article on basic brake setup:

    Adjusting Your Sheet Metal Brake : Irvan-Smith, Inc.

    With a finger brake the exact bend radius is going to take some trial and error to dial in. Setting the fingers back will give a larger bend radius, as will bending with the angle installed on the apron.

  3. #3
    Join Date
    Mar 2004
    Location
    Edison Washington USA
    Posts
    10,342
    Post Thanks / Like
    Likes (Given)
    964
    Likes (Received)
    5344

    Default

    the alloy of the aluminum, and the thickness, both matter quite a bit.

    Here is a chart which shows how it varies depending on the alloy or metal used.
    Minimum Recommended Bend Radius Chart from American Machine Tools Company

  4. #4
    Join Date
    Sep 2010
    Location
    Oklahoma City, OK
    Posts
    4,249
    Post Thanks / Like
    Likes (Given)
    730
    Likes (Received)
    1784

    Default

    Awesome, thank you both!

  5. #5
    Join Date
    Jul 2004
    Location
    Houston, TX USA
    Posts
    29,659
    Post Thanks / Like

    Default

    a small finger brake
    It will be surprising how the act of bending will simply move the stock - without a back up to prevent that happening

    Thumbnail is one I made for my Pexto before I sold it
    Attached Thumbnails Attached Thumbnails dcp_0726.jpg  

  6. #6
    Join Date
    Sep 2010
    Location
    Oklahoma City, OK
    Posts
    4,249
    Post Thanks / Like
    Likes (Given)
    730
    Likes (Received)
    1784

    Default

    Brake doesn't currently have a back gauge but one is on my list to fabricate.

    I'd not mind some pics of shop made arrangements if anyone has some handy.

  7. #7
    Join Date
    Mar 2005
    Location
    Kansas
    Posts
    7,432
    Post Thanks / Like
    Likes (Given)
    426
    Likes (Received)
    3406

    Default

    An apron brake won't give a smooth radius like a press brake. If that's important, you have the wrong tool.

    Standard is to set the top leaf back two times your material thickness.

  8. Likes steve-l liked this post
  9. #8
    Join Date
    Sep 2010
    Location
    Oklahoma City, OK
    Posts
    4,249
    Post Thanks / Like
    Likes (Given)
    730
    Likes (Received)
    1784

    Default

    Quote Originally Posted by gbent View Post
    An apron brake won't give a smooth radius like a press brake. If that's important, you have the wrong tool.

    Standard is to set the top leaf back two times your material thickness.
    Perfect.

    No need for perfect radius here, just building some small boxes and sheet metal panels to replace some that have been damaged over the years.

    It seems that if the brake is good for 16ga mild, that about 20ga stainless is its limit. That a fair estimate?

  10. #9
    Join Date
    Jan 2010
    Country
    UNITED STATES
    State/Province
    North Carolina
    Posts
    170
    Post Thanks / Like
    Likes (Given)
    267
    Likes (Received)
    90

    Default

    Yes, generally speaking you need to derate by 4 gauges for stainless.


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •